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Articles 68821 - 68850 of 196860

Full-Text Articles in Engineering

Global Opportunities To Increase Agricultural Independence Through Phosphorus Recycling, Stephen M. Powers, R. B. Chowdhury, G. K. Macdonald, A, H.W. Beusen, A. F. Bouwman, S. E. Hampton, Brooke K. Mayer, M. L. Mccracklin, D. A. Vaccari Apr 2019

Global Opportunities To Increase Agricultural Independence Through Phosphorus Recycling, Stephen M. Powers, R. B. Chowdhury, G. K. Macdonald, A, H.W. Beusen, A. F. Bouwman, S. E. Hampton, Brooke K. Mayer, M. L. Mccracklin, D. A. Vaccari

Civil and Environmental Engineering Faculty Research and Publications

Food production hinges largely upon access to phosphorus (P) fertilizer. Most fertilizer P used in the global agricultural system comes from mining of nonrenewable phosphate rock deposits located within few countries. However, P contained in livestock manure or urban wastes represents a recyclable source of P. To inform development of P recycling technologies and policies, we examined subnational, national, and global spatial patterns for two intersections of land use affording high P recycling potential: (a) manure‐rich cultivated areas and (b) populous cultivated areas. In turn, we examined overlap between P recycling potential and nation‐level P fertilizer import dependency. Populous cultivated …


Comment On “Patented Blunderings, Efficiency Awareness, And Self-Sustainability Claims In The Pyrolysis Energy From Waste Sector”, Patrick J. Mcnamara, Daniel Zitomer, Zhongzhe Liu Apr 2019

Comment On “Patented Blunderings, Efficiency Awareness, And Self-Sustainability Claims In The Pyrolysis Energy From Waste Sector”, Patrick J. Mcnamara, Daniel Zitomer, Zhongzhe Liu

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.


Field Obstacle Identification For Autonomous Tractor Applications, Caleb Lindhorst Apr 2019

Field Obstacle Identification For Autonomous Tractor Applications, Caleb Lindhorst

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

New technologies are being developed to meet the growing demand for agricultural products. Autonomous tractors are one of the many solutions to address this demand. Obstacle detection and avoidance is an important consideration for safe operation of any autonomous machine. Three field obstacles were chosen to be identified in this thesis work: tractors, round bales, and center pivots. Limited research work was found on the identification of center pivot detection.

Feasibility of using low cost LIDARs was considered for the detection of tractors, bales, and agricultural center pivots. Performance of LIDARs in different lighting conditions, different colors of obstacles, accuracy …


Initial Development Of Advanced, High-Rate Treatment Process For Wet Weather Flows, Paige Elyse Peters Apr 2019

Initial Development Of Advanced, High-Rate Treatment Process For Wet Weather Flows, Paige Elyse Peters

Master's Theses (2009 -)

Billions of gallons of untreated water are discharged into lakes and rivers every year due to combined and sanitary sewer overflows during high-intensity precipitation events. Combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) pose both environmental and public health risks due to potential human contact with contaminated water. To address the overflow issue, a novel, advanced, high-rate wet weather treatment process was investigated. The high-rate treatment process combined chemically enhanced primary treatment (CEPT) with an advanced oxidation process (AOP) using ozone to rapidly remove total suspended solids (TSS) and chemical oxygen demand (COD), inactive E. coli, and oxidize the …


Sensor Intrusion Detection In Control Systems Using Estimation Theory, Jiayi Su Apr 2019

Sensor Intrusion Detection In Control Systems Using Estimation Theory, Jiayi Su

Master's Theses (2009 -)

In this thesis, two different approaches to sensor intrusion detection are presented. In the first approach, an estimation algorithm using a bank of Kalman Filters is designed that is capable of estimating the intrusion signal when sensors are affected in control systems. The mathematical models of the control system will be established and the system measurement will be shown and after that, various false signals, such as constant-type and ramp-type signal, will be selected as the intrusion signal to affect the system output mentioned above. The system measurement will be tested based on a bank of Kalman Filters. The probabilities …


State Estimation For Various Systems With Partially Unknown Dynamics, Abdulelah Rajeh Alshareef Apr 2019

State Estimation For Various Systems With Partially Unknown Dynamics, Abdulelah Rajeh Alshareef

Master's Theses (2009 -)

This thesis is on state estimation for various system and measurement models with uncertain dynamics. The uncertain dynamics may be due to imprecise system modeling or change in parameters due to varying environmental conditions. Uncertainty may be a result of malicious acts such as hacking of sensors or actuators in the system. Uncertainty may also be a result of external disturbances whose waveforms, magnitudes and arrival times may not be known. These types of model uncertainties will be considered and different estimators will be implemented to deal with such uncertainties in state estimation. In this thesis, for linear stochastic systems …


Detection And Characterization Of Actuator Attacks Using Kalman Filter Estimation, Yuqin Weng Apr 2019

Detection And Characterization Of Actuator Attacks Using Kalman Filter Estimation, Yuqin Weng

Master's Theses (2009 -)

In this thesis, two discrete-time control systems subject to noise, are modeled, analyzed and estimated. These systems are then subjected to attack by false signals such as constant and ramp signals. In order to find out how and when the control systems are being attacked by the false signals, several detection algorithms are applied to the systems. This work focuses on actuator attack detection. To detect the presence of false actuator signals, a bank of Kalman filters is set up which uses adaptive estimation and conditional probability density functions for detecting the false signals. The individual Kalman filters are each …


The Characterization Of Char Particle Morphology And Its Effects On Combustion, Scott Jorgensen Apr 2019

The Characterization Of Char Particle Morphology And Its Effects On Combustion, Scott Jorgensen

Master's Theses (2009 -)

Char particle combustion typically occurs under internal diffusion control, which results in inter-particle reactant gradients. Reactant concentrations throughout the char’s carbon structure must be known in order to predict overall particle reaction rates. These concentrations can be predicted by analytical models; however, effects of char morphology are typically ignored within these simplified models. In order to incorporate these effects, the morphology of Illinois coal #6 was studied by visualizing their structure in three-dimensions through the use of micro-computed tomography. Morphological characteristics of macro-porosity, macro-porosity location, and wall thickness were then measured for the sampled char particles. The sampled char particles …


Shock Compaction Of Graphene Doped Yttria Stabilized Zirconia: An Experimental And Computational Study, Christopher Rueben Johnson Apr 2019

Shock Compaction Of Graphene Doped Yttria Stabilized Zirconia: An Experimental And Computational Study, Christopher Rueben Johnson

Master's Theses (2009 -)

Yttria stabilized zirconia (YSZ) is a broadly used ceramic due to its impeccable hardness and thermal stability. Limitations of the material, however, subsist within its fracture toughness. Literature indicates that shock consolidation may enable production of composite YSZ and graphene mixtures with improved fracture toughness and other material properties while maintaining the material’s nanostructure dimensionality. Therefore, investigation of the compaction phenomena at non-equilibrium states will provide informative results to be used in the fabrication of bulk graphene-YSZ composites. Computational molecular dynamics (MD) simulations and impact experiments are conducted to explore and characterize the dynamic response of the YSZ variants. Molecular …


Liquid Flowmeter Using Thermal Measurement; Design And Application, Woojae Chung Apr 2019

Liquid Flowmeter Using Thermal Measurement; Design And Application, Woojae Chung

Master's Theses (2009 -)

This thesis presents flowmeter devices which can measure flowrate, pressure and temperature offlowing liquid samples using thermal measurement method. Typical thermal mass flowmeter usesthermal properties of materials to obtain flow features only for gases. We designed and fabricatedflowmeter devices with various functionalities such as: measuring properties of flowing liquid andidentifying the type of liquid samples.Thermal measurement methods using temperature sensor is a key of our flowmeter’s workingprinciple. The thermal mass flowmeter consists of a glass capillary, a tungsten wire heater, and aresistance temperature detector (RTD) sensor. The heater and sensors are integrated on …


Correlations Between Shoulder Rotational Motion, Strength Measures And Throwing Biomechanics In Collegiate Baseball Pitchers, Austin William Higgins Apr 2019

Correlations Between Shoulder Rotational Motion, Strength Measures And Throwing Biomechanics In Collegiate Baseball Pitchers, Austin William Higgins

Master's Theses (2009 -)

Pitching involves high stresses to the arm that may alter soft tissue responsible for controlling biomechanics. It has been hypothesized that imbalances in strength and flexibility of the dominant shoulder lead to decreased performance and increased injury risk, but it is not fully known what specific pitching biomechanics are altered. There is a critical need to determine correlations between shoulder rotational strength, range of motion and pitching kinetics. Without such knowledge, identifying potential for injury from shoulder imbalances will likely remain difficult and invasive. The goal of this study was to determine correlations between shoulder rotational strength and range of …


Electrocoagulation-Electrooxidation For Mitigating Trace Organic Compounds In Model Source Waters, Donald R. Ryan Apr 2019

Electrocoagulation-Electrooxidation For Mitigating Trace Organic Compounds In Model Source Waters, Donald R. Ryan

Master's Theses (2009 -)

Conventional coagulation and oxidation are well suited for many drinking water operations to meet regulatory requirements for safe drinking water. However, these processes require auxiliary chemicals and materials that must be transported from off-site, which increases complexity of operations, and can pose difficulties for small treatment systems. Electrochemistry offers an innovative method to induce coagulation and oxidation processes for water treatment. Electrocoagulation (EC) together with electrooxidation (EO) is an attractive option for drinking water treatment systems because these processes generate iron coagulants using iron EC electrodes and oxidants (e.g., free chlorine and reactive oxygen species) using boron-doped diamond EO electrodes. …


Kinetic Analysis Of Biosolid Pyrolysis, William Regan Kreutter Apr 2019

Kinetic Analysis Of Biosolid Pyrolysis, William Regan Kreutter

Master's Theses (2009 -)

Waste reduction and energy recovery have been an environmental focus. Many of these solutions involve the thermal degradation of waste, such as household garbage or organic waste. To help reduce the negative environmental impact associated with processes like incineration, methods have been developed to utilize the carbonaceous material and energy contained in waste. Wastewater treatment plants are responsible for collecting and cleaning billions of gallons of sewage and stormwater each year. The water collected goes through multiple cleaning stages before being discharged into surface water. Sewage sludge, commonly referred to as biosolids, are produced during the process. Biosolids are carbon …


Development Of A Quasi-Monte Carlo Method For Thermal Radiation, Joseph Farmer Apr 2019

Development Of A Quasi-Monte Carlo Method For Thermal Radiation, Joseph Farmer

Master's Theses (2009 -)

Radiative heat transfer in participating media is among the most challenging computational engineering problems due to the complex nonlinear, nonlocal nature of radiation transport. Many approximate methods have been developed in order to resolve radiative heat transfer in participating media; but approximate methods, by the nature of their approximations, suffer from various shortcomings both in terms of accuracy and robustness. The only methods that can resolve radiative transfer accurately in all configurations are the statistical Monte Carlo-based methods. While the Monte Carlo (MC) method is the most accurate method for resolving radiative heat transfer, it is also notoriously computationally prohibitive …


Ergonomics Study Of A Helmet-Mounted Augmented Reality System For Coal Power Plant Workers, Ashley M. Toll Apr 2019

Ergonomics Study Of A Helmet-Mounted Augmented Reality System For Coal Power Plant Workers, Ashley M. Toll

Master's Theses (2009 -)

Augmented reality (AR) is a technology that combines real and virtual information presented to the user in an interactive way in real time. The Microsoft HoloLens and RealWear HMT-1 are two common types of head-mounted AR available to industrial field workers. These two AR systems were tested on how they affected indicators of eye strain and forces of the neck and shoulder muscles for electric utility power plant operators while they performed five routine inspection tasks using coal burning equipment. The inspection tasks were conducted under three conditions: HoloLens, HMT-1, and absence of AR (normal). The duration of the inspection …


Improved Reliability Of Stormwater Detention Basin Performance Through Water Quality Data-Informed Real-Time Control, Sazzad Sharior Apr 2019

Improved Reliability Of Stormwater Detention Basin Performance Through Water Quality Data-Informed Real-Time Control, Sazzad Sharior

Master's Theses (2009 -)

The objective of stormwater detention basins is to capture stormwater runoff to reduce and delay peak flow and to improve the water quality. These objectives can be improved upon by actively controlling the outflow of the basins rather than traditional passive outflow structures. There are studies demonstrating the performance of the active controls that respond in real-time to basin hydraulics, detention time, and rainfall forecasts. We hypothesize that the performance of these active controls can be improved upon by incorporating real-time water quality data streams into the control algorithm. Furthermore, we hypothesize that performance of these active controls also depends …


Computational Characterization Of The Cellular Origins Of Electroencephalography, Shane Hesprich Apr 2019

Computational Characterization Of The Cellular Origins Of Electroencephalography, Shane Hesprich

Master's Theses (2009 -)

Electroencephalography (EEG) is a non-invasive technique used to measure brain activity. Despite its near ubiquitous presence in neuroscience, very little research has gone into connecting the electrical potentials it measures on the scalp to the underlying network activity which generates those signals. This results in most EEG analyses being more macroscopically focused (e.g. coherence and correlation analyses). Despite the many uses of macroscopically focuses analyses, limiting research to only these analyses neglects the insights which can be gained from studying network and microcircuit architecture. The ability to study these things through non-invasive techniques like EEG depends upon the ability to …


Impact Of Electrocoagulation Pretreatment On E. Coli Mitigation Using Electrooxidation, William Mcgregor Lynn Apr 2019

Impact Of Electrocoagulation Pretreatment On E. Coli Mitigation Using Electrooxidation, William Mcgregor Lynn

Master's Theses (2009 -)

Small drinking water systems serve approximately 20% of the US population, but they can struggle to comply with the Total Coliform Rule and the Disinfectant and Disinfection Byproduct Rule. Issues with insufficient funds to effectively treat the water and difficulties with the transportation of required chemicals can affect compliance. Electrochemical processes may offer an alternative approach for small water systems as they have demonstrated some advantages over traditional treatments, such as reduced handling and storage of chemicals and cost effectiveness. Sequential electrochemical processes have yet to be tested for the treatment of E. coli in drinking waters. In this study, …


Parametric Study Of Hypoplasticity Constitutive Model For Granular Media Via The Discrete Element Method, Yufei Zhou Apr 2019

Parametric Study Of Hypoplasticity Constitutive Model For Granular Media Via The Discrete Element Method, Yufei Zhou

Master's Theses (2009 -)

Granular media, as a general definition, includes a large class of materials, such as cereal grains; pharmaceutical tablets and capsules; geomaterials, such as sand; and the masses of rock and ice in planetary rings. Alternatively, a granular material could consist of highly fractured rock masses regarded as cracked elastic solids. In all cases, a very important property of granular media is their ability to yield, that is, exhibit irreversible deformation properties. Because the granular elastic modulus ‘G’ is the key relevant stress parameter, there is an interesting and nagging question as to the microscopic origins of the stress scales assumed …


Profile Synthesis Of Prismatic-Prismatic Variable Joints For Use In Reconfigurable Mechanisms, Ryan Daniel Callahan Apr 2019

Profile Synthesis Of Prismatic-Prismatic Variable Joints For Use In Reconfigurable Mechanisms, Ryan Daniel Callahan

Master's Theses (2009 -)

Reconfigurable mechanisms provide increased flexibility in machine design and can be used in a variety of applications. Variable joints in reconfigurable mechanisms allow for machine designs that better optimize space and resources. This thesis uses a configuration space analysis to determine the motion profiles of Prismatic-Prismatic higher variable joints. Prismatic-Prismatic variable joints have never been analyzed or synthesized. In addition, no variable joints of any type have been considered with two-dimensional contact points. Variable joints enable the creation of Type II Mechanisms with Variable Topology, mechanisms whose topology changes due to changes in joint geometry. The goal of this synthesis …


Power Divider Miniaturization With A Variable Load, Amanda Jensen Apr 2019

Power Divider Miniaturization With A Variable Load, Amanda Jensen

Master's Theses (2009 -)

A 3 Tesla (127.72 MHz) Magnetic Resonance system is able to scan with both the body coil and surface coil at the same time due to a technology called simultaneous acquisition, which uses a 4-port power divider, typically a quad hybrid. This functions at 127.72 MHz. The goal is to replicate this function at 1.5 Tesla field strength (63.86 MHz), but to do so would require the power divider to double in size. This space is not available, so methods of miniaturizing the design were investigated. It was found that slow wave structures cannot shrink the quadrature hybrid design enough …


Lumped Parameter Modeling And Parameter Investigation Of An Electrohydraulic Crimping Hand Tool, Eric Norquist Apr 2019

Lumped Parameter Modeling And Parameter Investigation Of An Electrohydraulic Crimping Hand Tool, Eric Norquist

Master's Theses (2009 -)

A lumped parameter model of a hand-held electrohydraulic tool was developed. The tool modeled was a Milwaukee Tool M18 12 Ton Crimper. First principle approaches were used to develop state-space models for each of the subsystems in the tool. The included subsystems were the tool motor and gear train, pump, return valve, and cylinder. The subsystem models were combined into a comprehensive eleventh-order nonlinear dynamic tool model. The tool model has two inputs and three outputs. The model inputs were the motor voltage and opening the return valve. The outputs were the motor current, application time, and retraction time. Each …


Microfabrication And Characterization Of Freestanding And Integrated Carbon Nanotube Thin Films, Derric Benjamin Syme Apr 2019

Microfabrication And Characterization Of Freestanding And Integrated Carbon Nanotube Thin Films, Derric Benjamin Syme

Theses and Dissertations

This work chronicles the fabrication of two unique thin films using carbon nanotubes. The first is a carbon film made primarily from vertically grown carbon nanotubes (CNTs) and rolled into lateral alignment. The second is an insulating film created by CNTs as a scaffolding to create a porous silica layer. Each topic represents a different method of utilizing CNTs for thin-film fabrication.Investigation of an entirely carbon thin film, comprised of aligned and laterally oriented carbon nanotubes was performed. The thin film was strengthened by deposition of amorphous carbon for a total thickness of <<> 5 µm. This thickness is thinner than …


Analysis Of Distortion Transfer And Generation Through A Fan And A Compressor Using Full-Annulus Unsteady Rans And Harmonic Balance Approaches, Daniel Robert Soderquist Apr 2019

Analysis Of Distortion Transfer And Generation Through A Fan And A Compressor Using Full-Annulus Unsteady Rans And Harmonic Balance Approaches, Daniel Robert Soderquist

Theses and Dissertations

Understanding distortion transfer and generation through fan and compressor blade rows is able to assist in blade design and performance prediction. Using full annulus unsteady RANS simulations, the effects of distortion as it passes through the rotor of a transonic fan at five radial locations (10%, 30%, 50%, 70%, and 90% span) are analyzed. The inlet distortion profile is a 90-degree sector with a 15% total pressure deficit. Fourier distortion descriptors are used in this study to quantitatively describe distortion transfer and generation. Results are presented and compared for three operating points (near-stall, design, and choke). These results are used …


Near Real-Time Flood Forecasts From Global Hydrologic Forecasting Models, Corey Nicholas Krewson Apr 2019

Near Real-Time Flood Forecasts From Global Hydrologic Forecasting Models, Corey Nicholas Krewson

Theses and Dissertations

This research assesses possible methods for extending the Streamflow Prediction Tool from a streamflow forecasting model to a flood extent forecasting model. This new flood extent forecasting model would allow valuable and easy to understand information be disseminated in a timely manner for flood preparation and flood response. The Height Above Nearest Drainage (HAND) method and AutoRoute method were considered for flood extent models but the HAND was the better option for its simple and quick computation as well as its viability on a global scale. Due to the importance of Digital Elevation Models (DEMs) in these flood extent models, …


Mesoscale Modeling Of Shape Memory Alloys By Kinetic Monte Carlo–Finite Element Analysis Methods, Adam David Herron Apr 2019

Mesoscale Modeling Of Shape Memory Alloys By Kinetic Monte Carlo–Finite Element Analysis Methods, Adam David Herron

Theses and Dissertations

A coupled kinetic Monte Carlo – Finite Element Analysis (kMC–FEA) method is developed with a numerical implementation in the Scalable Implementation of Finite Elements at NASA (ScIFEN). This method is presented as a mesoscale model for Shape Memory Alloy (SMA) material systems. The model is based on Transition State Theory and predicts the nonlinear mechanical behavior of the 1st order solid–solid phase transformation between Austenite and Martensite in SMAs. The kMC–FEA modeling method presented in this work builds upon the work of Chen and Schuh [1, 2]. It represents a “bottom-up” approach to materials modeling and could serve as a …


Revisiting The Butler-Mokrys Model For The Vapor-Extraction Process, Vijitha Mohan, Partho Neogi, Baojun Bai Apr 2019

Revisiting The Butler-Mokrys Model For The Vapor-Extraction Process, Vijitha Mohan, Partho Neogi, Baojun Bai

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamics of a process in which a solvent in the form of a vapor or gas is introduced in a heavy-oil reservoir is considered. The process is called the solvent vapor-extraction process (VAPEX). When the vapor dissolves in the oil, it reduces its viscosity, allowing oil to flow under gravity and be collected at the bottom producer well. The conservation-of-species equation is analyzed to obtain a more-appropriate equation that differentiates between the velocity within the oil and the velocity at the interface, which can be solved to obtain a concentration profile of the solvent in oil. We diverge from …


Modeling Land Subsidence Using Insar And Airborne Electromagnetic Data, Ryan G. Smith, R. Knight Apr 2019

Modeling Land Subsidence Using Insar And Airborne Electromagnetic Data, Ryan G. Smith, R. Knight

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Land subsidence as a result of groundwater overpumping in the San Joaquin Valley, California, is associated with the loss of groundwater storage and aquifer contamination. Although the physical processes governing land subsidence are well understood, building predictive models of subsidence is challenging because so much subsurface information is required to do so accurately. For the first time, we integrate airborne electromagnetic data, representing the subsurface, with subsidence data, mapped by interferometric synthetic aperture radar (InSAR), to model deformation. By combining both data sets, we are able to solve for hydrologic and geophysical properties of the subsurface to effectively model the …


Domain Adaption Via Feature Selection On Explicit Feature Map, Wan Yu Deng, Amaury Lendasse, Yew Soon Ong, Ivor Wai Hung Tsang, Lin Chen, Qing Hua Zheng Apr 2019

Domain Adaption Via Feature Selection On Explicit Feature Map, Wan Yu Deng, Amaury Lendasse, Yew Soon Ong, Ivor Wai Hung Tsang, Lin Chen, Qing Hua Zheng

Engineering Management and Systems Engineering Faculty Research & Creative Works

In Most Domain Adaption Approaches, All Features Are Used for Domain Adaption. However, Often, Not Every Feature is Beneficial for Domain Adaption. in Such Cases, Incorrectly Involving All Features Might Cause the Performance to Degrade. in Other Words, to Make the Model Trained on the Source Domain Work Well on the Target Domain, it is Desirable to Find Invariant Features for Domain Adaption Rather Than using All Features. However, Invariant Features Across Domains May Lie in a Higher Order Space, instead of in the Original Feature Space. Moreover, the Discriminative Ability of Some Invariant Features Such as Shared Background Information …


Underground Environment Aware Mimo Design Using Transmit And Receive Beamforming In Internet Of Underground Things, Abdul Salam Apr 2019

Underground Environment Aware Mimo Design Using Transmit And Receive Beamforming In Internet Of Underground Things, Abdul Salam

Faculty Publications

In underground (UG) multiple-input and multiple-output (MIMO), the transmit beamforming is used to focus energy in the desired direction. There are three different paths in the underground soil medium through which the waves propagates to reach at the receiver. When the UG receiver receives a desired data stream only from the desired path, then the UG MIMO channel becomes three path (lateral, direct, and reflected) interference channel. Accordingly, the capacity region of the UG MIMO three path interference channel and degrees of freedom (multiplexing gain of this MIMO channel requires careful modeling). Therefore, expressions are required derived the degrees of …